# SIGMA LINK vs CKcardio

The clearest difference is in-app purchases: SIGMA LINK at none against CKcardio's 2. SIGMA LINK also leads on iOS requirement (12.0 vs 26.5). CKcardio's advantage is update cadence (fortnightly vs every 4 months). On price, ads and device support there is nothing between them.

Both are free to download. CKcardio sells 2 in-app purchases, starting at $0.99 per month. SIGMA LINK asks for nothing beyond the download.

SIGMA LINK ships an update every 4 months, CKcardio fortnightly. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | SIGMA LINK | CKcardio |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.5 (8 ratings)](https://appshunter.io/ios/app/sigma-link/id1147984544/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 9.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Fortnightly** |
| Monetization | Free | — |
| Size | 76 MB | 2 MB |
| Requires iOS | **12.0** | 26.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [SIGMA-ELEKTRO GmbH](https://appshunter.io/developer/803939887) | [Christian Kany](https://appshunter.io/developer/448047781) |

## What reviewers say

### SIGMA LINK

[App page](https://appshunter.io/ios/app/sigma-link/id1147984544)

Easily transfer training data from compatible devices to your smartphone. View personal bests, statistics, and completed tracks. Sync all your training data, workouts, and sport profiles with cloud integration for constant access.

**Highlights:** Transfer training units, View training statistics, Track personal bests, Manage device settings, Sync with SIGMA CLOUD, Access workouts and sport profiles

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### CKcardio

[App page](https://appshunter.io/ios/app/ckcardio/id6792734818)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Mothly subscription | $0.99 | per month |
| Year subscription | $8.99 | per year |


## Frequently asked questions

### Is SIGMA LINK free?

SIGMA LINK is free to download, with no in-app purchases.

### Is CKcardio free?

CKcardio is free to download, with in-app purchases available.

### Do SIGMA LINK or CKcardio have ads?

Neither SIGMA LINK nor CKcardio shows ads.

### Which is updated more often, SIGMA LINK or CKcardio?

SIGMA LINK ships an update every 4 months, and CKcardio fortnightly. Most recently, SIGMA LINK was updated on October 20, 2026 and CKcardio on October 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*